The extent to which pain reduction is observed with an analgesic in a RCT may depend on the surgical procedure studied because if the procedure intrinsically is not very painful, then it will be more difficult to demonstrate a pain relief benefit. In the available published RCTS, IV acetaminophen was studied in surgeries associated with varying levels of pain, including Cesareans, total abdominal hysterectomy, tonsillectomy, coronary artery bypass grafting, thyroidectomy, hip or knee replacement, and laparoscopic cholecystectomy procedures. The average postoperative rest pain scores in the placebo arms of these studies ranged from 2.0 to 3.7 out of 10, and for dynamic pain, it ranged from 3 to 5 out of 10.